Electronic engine - air compressor system

ABSTRACT

An electronically controlled diesel engine for a vehicle which may act as an air compressor in addition to acting as a power source for the vehicle. When acting in the air compressor function, one end cylinder is converted to the function to provide compressed air to air tanks on the vehicle. The air from this combination compressor and power cylinder may be used to fill air tanks which provide air for braking in vehicles such as heavy trucks. The combination compressor and power cylinder has an exhaust isolation valve in the exhaust manifold to isolate an air collection area and a relief/check valve engaged on an upstream side to the air collection area and to an air tank in the air system for the vehicle on the downstream side. An electronic controller means controls the fuel injector for the combination compressor and power cylinder and the exhaust isolation valve. Various types of diesel engines may be modified to become an electronic engine-air compressor system in accordance with this invention.

BACKGROUND OF THE INVENTION

The present invention relates to an electronically controlled dieselengine for a vehicle which may act as an air compressor in addition toacting as a power source for the vehicle. When acting in the aircompressor function, one end cylinder is converted to the function toprovide compressed air to air tanks on the vehicle. The air from thiscombination compressor and power cylinder may be used to fill air tankswhich provide air for braking in vehicles such as heavy trucks. Varioustypes of diesel engines may be modified to become an electronicengine-air compressor system in accordance with this invention.

Prior Art

Heretofore, diesel engines have existed which may be temporarily act asair compressors. One type of prior art diesel engine which could act asan air compressor involved tapping off pressurized air output from theturbo charger from the intake manifold. This prior art diesel engine isshown in U.S. Pat. No. 4,429,532. Diesel engines have a sets ofcombustion cylinders which have pistons which cycle in the cylinderswhen the engines are operated. Should fuel be shut off to the fuelinjectors of one of these combustion cylinders during engine operationwhile maintaining the piston movement, efficient compression of airentering the cylinder will occur and exhausting to the exhaust manifold.The prior art diesel engine shown in U.S. Pat. No. 4,429,532 did nottake advantage of this air compression in the cylinder to pressurize airfor the vehicle air system.

Diesel engine cylinders have an intake valve and an exhaust valve. Theintake valves, exhaust valves and injection valves cycle open and closedto allow the pistons to reciprocally move in the cylinders through anintake stroke, a compression stroke, an expansion stroke, and an exhauststroke. Another prior art diesel engine electronically varied themovement of two or half of the pistons in the cylinders of an in-linefour cylinder diesel engine to reverse motor the impacted cylinders. Thefuel injectors in the reverse motoring cylinders would be shut off andthe compressed gas would be discharged via the intake valves to theintake manifold. An example of this type prior art engine is shown inU.S. Pat. No. 5,226,401. Although this engine did involve aircompression in an engine cylinder starved of fuel, there was a complexscheme involved in varying the movement of the intake and exhaust valvesfrom their normal cycling for combustion. Additionally, the engine shownin U.S. Pat. No. 5,226,401 was not engaged to the vehicle's air systemto allow controlled delivery of pressurized air. Air compressed in thisprior art engine was redirected to the intake manifold to assist inengine pollutant reduction.

Another type prior art engine with a compressor function is shown inU.S. Pat. No. 3,744,934 where some of the cylinders may be converted toa compressor function. An engine internal switching means was requiredto accomplish the dual function so as to vary intake and exhaust valvecycling.

None of the prior art mentioned diesel engines with air compressorfunctions could be easily manufactured from simple modifications to anexisting diesel engine exhaust system without varying intake and exhaustvalve cycling.

Heretofore, an electronically controlled diesel engine for a vehiclewhich may act as an air compressor has not been suggested which utilizesthe exhaust stroke of one piston of a cylinder of the engine, is capableof discharging the exhausted air to the vehicle air system, does notvary the cycling of the engine intake and exhaust valves and which maybe easily manufactured with simple modifications to an existing dieselengine.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the invention to provide anelectronically controlled diesel engine for a vehicle which may act asan air compressor which utilizes the exhaust stroke of one piston of acylinder of the engine to compress air in an isolated portion of theexhaust manifold.

A second object of the invention is to provide a diesel engine which mayact as an air compressor which is capable of discharging the exhaustedair to the vehicle air system to recharge an air tank in the air system.

A third object of the invention is to provide a diesel engine which mayact as an air compressor that does not vary the cycling of the engineintake and exhaust valves to achieve the air compression.

A fourth object of the invention is to provide a diesel engine which mayact as an air compressor which may be easily manufactured with simplemodifications to the exhaust manifold of an existing diesel engine.

All the objects of the invention are satisfied with an electronicallycontrolled diesel engine for a vehicle which when acting in the aircompressor function, one end cylinder is converted to the function toprovide compressed air to air tanks on the vehicle. More specifically,there is an exhaust isolation valve in the engine's common exhaustmanifold which closes to isolate the portion of the exhaust manifoldwhere the compressor cylinder discharges exhaust gases. This isolableportion of the exhaust manifold has a tap off to a relief/check valve.The discharge from this relief/check valve is directed to an air tank inthe vehicle's air system. When the combination compressor and powercylinder is shifted to the compressor function, the exhaust isolationvalve closes and the fuel injector for the cylinder secures injectingfuel due to signals from an electronic controller for the engine. Airpressure builds up in the isolated section of the exhaust manifold asthe cylinder continues to cycle with the engine continuing to run. Whenthe air pressure achieves a preset value, the relief/check valve opensto transfer the compressed air to the air tank. When the air tanksachieve a present pressure, the exhaust isolation valve opens to releasethe exhaust gases to the normal discharge path and the relief/checkvalve closes as pressure in the previously isolated portion of themanifold decreases.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become more apparentupon perusal of the detailed description thereof and upon inspection ofthe drawings in which:

FIG. 1 is a perspective view of a diesel engine engaged to an air tankof a vehicle air system in accordance with this invention.

FIG. 2 is a diagrammatic plan partially sectional view of the engine ofFIG. 1 with a combination compressor and power cylinder operating in apower generation mode.

FIG. 3 is a diagrammatic plan partially sectional view of the engine ofFIG. 1 with a combination compressor and power cylinder operating in anair compression mode.

FIG. 4 is a partial diagrammatic cutaway view of the combinationcompressor and power cylinder of FIG. 2.

FIG. 5 is a partial diagrammatic cutaway view of the combinationcompressor and power cylinder of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in greater detail, in FIGS. 1 to 5, thereis shown an electronically controlled diesel engine 10 for a vehicle 101(not shown) which may act as an air compressor in addition to acting asa power source for the vehicle 101 made in accordance with thisinvention. The engine 10 includes an engine block 11 with cylinder bores12 to define cylinders 13. Within each cylinder 13 is a piston 14 toreciprocally move in the cylinders 13 through an intake stroke, acompression stroke, an expansion stroke, and an exhaust stroke when theengine 10 operates. Each said piston 14 is mechanically engaged to acrank shaft 51 (not shown). Each cylinder 13 additionally has an intakevalve 21, an exhaust valve 22, and a fuel injector 23. The intake valve21 and the exhaust valve 22 open and close in concert with pressurizedinjection of fuel by the fuel injector 23 to cause the four separatestrokes of the piston 14. The engine 10 includes an intake manifold 15,engaged to the engine block 11, which defines an intake manifold passage16 and a plurality of interconnected intake manifold branch passages 17.The intake manifold branch passages 17 are in fluid communication withthe intake valves 21.

The engine 10 further includes a turbocharger 18 having an incomingturbo air compressor 24 and an exhaust gas driven turbine 25. Thecompressor 18 is operatively connected to the intake manifold 16 by anintake conduit 26 providing supercharged air to combustion chambers 27of the cylinders 13. A cooler 47 is interposed in the intake conduit 26between the compressor 18 and the intake manifold passage 16. An exhaustmanifold 28 is engaged to the engine block 11 for conducting gas fromthe exhaust valves 22 and hence the combustion chambers 27. The exhaustmanifold 28 defines an exhaust manifold passage 29 and a plurality ofinterconnected exhaust manifold branch passages 30. The exhaust manifoldbranch passages 30 are in fluid communication with the exhaust valves22. The exhaust gas turbine 25 is operatively connected to the exhaustmanifold passage 29 by an exhaust gas conduit 32. Exhaust gas from thecombustion chambers 27 drives the turbine 25 which in turn drives theturbo air compressor 24 in a conventional manner.

One end cylinder 13 is designated as a combination compressor and powercylinder 19 to provide compressed air upon demand to an air tank 102 inthe air system 103 (not shown) on the vehicle 101. The combinationcompressor and power cylinder 19 may operate in either a powergeneration mode as shown in FIGS. 2 and 4, or; the combinationcompressor and power cylinder 19 may also operate in an air compressionmode as shown in FIGS. 3 and 5. More specifically, there is an exhaustisolation valve 33 in the exhaust manifold branch passage 30 engaged tothe exhaust valve 22 for the combination compressor and power cylinder19. When the exhaust isolation valve 33 closes, an air collection area34 of the exhaust manifold branch passage 30 associated with thecombination compressor and power cylinder 19 is isolated. The exhaustisolation valve 33 is shown as a flapper valve, however, it may be anyvalve which will isolate the air collection area to accumulate airpressure increases and will also provide little head loss when theexhaust isolation valve 33 is open. The air collection area 34 isoperatively engaged to a relief or one way check valve 35 through an airsupply line 36 on an upstream side of the relief/check valve 35. Therelief/check valve 35 is set to open a preset value of air pressure onthe upstream or the air collection area 34 side of the relief/checkvalve 35. In the preferred embodiment, the relief/check valve 35 willopen when the pressure in the air collection area 34 reaches or exceedsforty pounds per square inch gauge (40 psig). The discharge from therelief/check valve 35 is directed on the downstream side to the air tank102 through air piping 41. There is an air dryer 42 operatively engagedin the flow path in air piping 41 between the relief/check valve 35 andthe air tank 102 in the air system 103.

The engine 10 has an electronic controller means 93 (not shown) of typecommonly used on modern day diesel engines. The electronic controllermeans 93 which may be programmable controls the operation of the exhaustisolation valve 33 and the fuel injector 23 of the combinationcompressor and power cylinder 19. This control results in thecombination compressor and power cylinder 19 shifting between the powergeneration and air compression modes. The air system 103 containspressure sensors 111 (not shown) which detect pressure in the air tank102. The pressure sensors 111 provide input signals to the electroniccontroller means 93 so the electronic controller means will shift tobetween the combination compressor and power cylinder 19 between thepower generation and air compression modes. During the power generationmode, the electronic controller means 93 allows normal injection of fuelthrough the fuel injector 23 of the combination compressor and powercylinder 19 to the combustion chamber 27 and maintains the exhaustisolation valve 33 in an open position to allow passage of exhaust gasesto the exhaust gas conduit 32. When air pressure in the air tank 102,reaches a preset value, the electronic controller means 93 shifts thecombination compressor and power cylinder 19 to the air compression modeas follows. Fuel injection through the fuel injector 23 of thecombination compressor and power cylinder 19 is stopped. The piston 14of the combination compressor and power cylinder 19 continues to cycleas does the intake valve 21 and the exhaust valve 22. This cycling ofthe piston 14 causes the air collection area 34 to be purged ofcombustion gases. The preferred number of piston 14 cycles is when five(5) times the volume of the air collection area 34 has flowed throughthe air collection area 34. This should prevent contamination of the airsystem 103 of gaseous combustion products. After the air collection area34 is purged, the electronic controller means 93 closes the exhaustisolation valve 33 to isolate the air collection area 34. As a resultair pressure builds up in the air collection area 34 as the piston 14continues to cycle in the combination compressor and power cylinder 19.When air pressure in the air collection area 34 reaches a preset value,preferably 40 psig, the relief/check valve will open dischargingpressurized air to the air tank 102 through the air dryer 42. Once airpressure in the air tank 102 increases to a preset value, preferably 120psig, the electronic controller means 93 will open the exhaust isolationvalve 33. This will cause a pressure reduction in the air collectionarea 34 and as a result cause the relief/check to close. The electroniccontroller means 93 will then allow operation of the fuel injector 23for the combination compressor and power cylinder 19 to return thecylinder to the power generation mode.

The electronic controller means 93 will shift the combination compressorand power cylinder 19 to the air compression mode whenever the pressurein the air tank 102 or in the air system 103 is less than a highsetpoint of preferably approximately 120 psig and the driver is notdepressing an accelerator pedal 108 (not shown) of the vehicle 101. Thecylinder 19 will return to the power generation mode when air pressurereaches 120 psig. This higher setpoint will ensure air recharging of theair tank 102 occurs only when there is no power demand on the engine 10.The electronic controller means 93 will shift the combination compressorand power cylinder 19 to the air compression mode whenever the pressurein the air tank 102 or in the air system 103 falls below a low setpointof preferably approximately 100 psig regardless of the whether theaccelerator pedal 108 is depressed and stay in the air compression modeuntil air pressure reaches 100 psig. This lower setpoint ensures thatthat there will be air for braking in the air tank 102 regardless ofpower needs. There may also be a dash board mounted indicating lamp 109(not shown) indicating when the combination compressor and powercylinder 19 is in the air compression mode.

Various types of diesel engines may be converted to an engine 10 inaccordance with this invention by merely replacing the factory suppliedexhaust manifold branch passage 30 with one with an exhaust isolationvalve 33 and a relief/check valve engaged to an air tank 102, by addinga pressure sensor 111 to the air system 103 which provides signals tothe electronic controller means 93, and by reprogramming the electroniccontroller means 93 in accordance with the above described controlscheme.

As described above, the engine 10 with the combination compressor andpower cylinder 19 of the present invention provides a number ofadvantages, some of which have been described above and others of whichare inherent in the invention. Also modifications may be proposed to theengine 10 with the combination compressor and power cylinder 19 withoutdeparting from the teachings herein. Accordingly, the scope of theinvention is only to be limited as necessitated by the accompanyingclaims.

We claim:
 1. An electronically controlled diesel engine for a vehiclewith an accelerator pedal, an air system and an air tank for producingpower and for compressing air to replenish the air tank, comprising:a.an engine block; b. cylinder bores in said engine block to definecylinders; c. a piston in each said cylinder; d. each said pistonengaged to a crank shaft; e. each said cylinder has an intake valve, anexhaust valve and a fuel injector; f. an electronic controller means forcontrolling said fuel injectors; g. an exhaust manifold engaged to saidengine block; h. said exhaust manifold having exhaust manifold branchpassages corresponding to each of said cylinders and a common exhaustvalve passage; i. said exhaust manifold branch passages in fluidcommunication with said exhaust valves and said exhaust valve passage;j. an end cylinder of one of said cylinders being designated as acombination compressor and power cylinder; k. said combinationcompressor and power cylinder having an exhaust isolation valve in saidexhaust manifold branch passage in fluid communication with said exhaustvalve for said combination compressor and power cylinder; l. saidelectronic controller means capable of securing fuel injection throughsaid fuel injector for said combination compressor and power cylinder toenter into an air compression mode; m. said electronic controller meanscapable of closing said exhaust isolation valve upon a sensed airpressure reduction in the air tank to isolate an air collection area insaid exhaust valve manifold branch passage for said combinationcompressor and power cylinder while in said air compression mode; n. arelief/check valve functionally engaged to said air collection area onan upstream side and to the air tank through air piping on a downstreamside; o. said relief/check valve set to open upon a preset air pressurein said air collection area to supply air from said air collection areato the air tank; and p. said electronic controller means capable ofopening said exhaust isolation valve upon a sensed air pressure increasein the air tank to allow exhaust flow to pass through said exhaust valvemanifold branch passage for said combination compressor and powercylinder to said exhaust manifold passage to enter into a powergeneration mode; q. said relief/check valve set to close upon a presetreset air pressure in said air collection area to isolate said aircollection area from the air tank; and r. said electronic controllermeans capable allowing fuel injection through said fuel injector forsaid combination compressor and power cylinder while in a powergeneration mode.
 2. The electronically controlled diesel engine of claim1, wherein there is an air dryer operatively engaged between saidrelief/check valve and the air tank.
 3. The electronically controlleddiesel engine of claim 1, wherein:a. said electronic controller meanssequentially secures fuel injection through fuel injector for saidcombination compressor and power cylinder before closing said exhaustisolation valve when entering said air compression mode to allow purgingof a predetermined volume of gases through said air collection area. 4.The electronically controlled diesel engine of claim 3, wherein:a. saidpredetermined volume of gas purging is five times the volume of said aircollection area.
 5. The electronically controlled diesel engine of claim1, wherein:a. said preset air pressure in said air collection area forsaid relief/check valve to open is 40 psig.
 6. The electronicallycontrolled diesel engine of claim 1, wherein:a. said electroniccontroller means is additionally comprised of a sensor of whether theaccelerator pedal is depressed; and b. said electronic controller meanswill secure fuel injection through said fuel injector for saidcombination compressor and power cylinder and close said exhaustisolation valve to enter said air compression mode when air pressure inthe air tank reaches a high setpoint and said electronic controllermeans senses that the accelerator pedal is not depressed.
 7. Theelectronically controlled diesel engine of claim 6, wherein said highsetpoint is approximately 120 psig.
 8. The electronically controlleddiesel engine of claim 7, wherein:a. said electronic controller meanswill secure fuel injection through said fuel injector for saidcombination compressor and power cylinder and close said exhaustisolation valve to enter said air compression mode when air pressure inthe air tank reaches a low setpoint.
 9. The electronically controlleddiesel engine of claim 8, wherein said low setpoint is approximately 100psig.